Inverter and method for measuring phase currents in an electric machine

    公开(公告)号:US11105836B2

    公开(公告)日:2021-08-31

    申请号:US16746444

    申请日:2020-01-17

    Abstract: A three-phase load is powered by a PWM (e.g., SVPWM) driven DC-AC inverter having a single shunt-topology. A shunt voltage and a branch voltage of the inverter (across a transistor to be calibrated) are measured during a second period of each SVPWM sector, and the drain-to-source resistance of the calibrated transistor is calculated. During the fourth period of each SVPWM sector, the branch voltage is measured again, and another branch voltage across another transistor is measured. Using the drain-to-source resistance of the calibrated transistor and the voltage across the calibrated transistor measured during the fourth period, the phase current through the calibrated transistor is calculated. Using the other branch voltage measured during the fourth period and the drain-to-source resistance of its corresponding transistor (known from a prior SVPWM sector), the phase current through that transistor is calculated. From the two calculated phase currents, the other phase current can be calculated.

    Inverter and method to measure junction temperature for thermal protection

    公开(公告)号:US12264976B2

    公开(公告)日:2025-04-01

    申请号:US17836817

    申请日:2022-06-09

    Abstract: A three-phase load is powered by an SPWM driven inverter having a single shunt-topology. During operation, drain-to-source resistances of transistors of each branch of the inverter are determined. Interpolation is performed on assumed drain-to-source resistances of the transistors for different temperatures to produce a non-linear model of drain-to-source resistance to temperature for the transistors, and the drain-to-source resistances determined during operation and the non-linear model are used to estimate temperature values of the transistors. Driving of the inverter can be adjusted so that conductivity of each branch is set so that power delivered by that branch is as high as possible without exceeding an allowed drain current threshold representing a threshold junction temperature. In addition, driving of the inverter can be ceased if the temperature of a transistor exceeds the threshold temperature.

    Inverter and method for measuring phase currents in an electric machine

    公开(公告)号:US11635453B2

    公开(公告)日:2023-04-25

    申请号:US17378226

    申请日:2021-07-16

    Abstract: A three-phase load is powered by a PWM (e.g., SVPWM) driven DC-AC inverter having a single shunt-topology. A shunt voltage and a branch voltage of the inverter (across a transistor to be calibrated) are measured during a second period of each SVPWM sector, and the drain-to-source resistance of the calibrated transistor is calculated. During the fourth period of each SVPWM sector, the branch voltage is measured again, and another branch voltage across another transistor is measured. Using the drain-to-source resistance of the calibrated transistor and the voltage across the calibrated transistor measured during the fourth period, the phase current through the calibrated transistor is calculated. Using the other branch voltage measured during the fourth period and the drain-to-source resistance of its corresponding transistor (known from a prior SVPWM sector), the phase current through that transistor is calculated. From the two calculated phase currents, the other phase current can be calculated.

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